International Classification of Headache Disorders

The International Classification of Headache Disorders (ICHD) is a detailed hierarchical classification of all headache-related disorders published by the International Headache Society. It is considered the official classification of headaches by the World Health Organization, and, in 1992, was incorporated into the 10th edition of their International Classification of Diseases (ICD-10). Each class of headache contains explicit diagnostic criteria—meaning that the criteria include quantities rather than vague terms like several or usually—that are based on clinical and laboratory observations.

The ICHD was first published in 1988 (now known as the ICHD-1). A second version, the ICHD-2, was published in 2004. The most current version, ICHD-3, was published in 2018.

ICHD 1, ICD10 G43: Migraine

 * Migraine without aura
 * Migraine with aura
 * Childhood periodic syndromes that are commonly precursors of migraine
 * Retinal migraine
 * Complications of migraine
 * Migraine-triggered seizure
 * Probable migraine

ICHD 2, ICD10 G44.2: Tension-type headache (TTH)

 * Infrequent episodic tension-type headache
 * Frequent episodic tension-type headache
 * Chronic tension-type headache
 * Probable tension-type headache

ICHD 3, ICD10 G44.0: Cluster headache and other trigeminal autonomic cephalalgias

 * Cluster headache
 * Paroxysmal hemicrania
 * Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)
 * Probable trigeminal autonomic cephalalgia

ICHD 4, ICD10 G44.80: Other primary headaches

 * Primary stabbing headache
 * Primary cough headache
 * Primary exertional headache
 * Primary headache associated with sexual activity
 * Hypnic headache
 * Primary thunderclap headache
 * Hemicrania continua
 * New daily persistent headache (NDPH)

ICHD 5, ICD10 G44.88: Headache attributed to head and/or neck trauma

 * Acute post-traumatic headache
 * Acute post-traumatic headache attributed to moderate or severe head injury
 * Acute post-traumatic headache attributed to mild head injury
 * Chronic post-traumatic headache
 * Chronic post-traumatic headache attributed to moderate or severe head injury
 * Chronic post-traumatic headache attributed to mild head injury
 * Acute headache attributed to whiplash injury
 * Chronic headache attributed to whiplash injury
 * Headache attributed to traumatic intracranial haematoma
 * Headache attributed to epidural haematoma
 * Headache attributed to subdural haematoma
 * Headache attributed to other head and/or neck trauma
 * Acute headache attributed to other head and/or neck trauma
 * Chronic headache attributed to other head and/or neck trauma
 * Post-craniotomy headache
 * Acute post-craniotomy headache
 * Chronic post-craniotomy headache

ICHD 6, ICD10 G44.81: Headache attributed to cranial or cervical vascular disorder

 * Headache attributed to ischaemic stroke or transient ischaemic attack
 * Headache attributed to ischaemic stroke (cerebral infarction)
 * Headache attributed to transient ischaemic attack (TIA)
 * Headache attributed to non-traumatic intracranial haemorrhage
 * Headache attributed to intracerebral haemorrhage
 * Headache attributed to subarachnoid haemorrhage (SAH)
 * Headache attributed to unruptured vascular malformation
 * Headache attributed to saccular aneurysm
 * Headache attributed to arteriovenous malformation (AVM)
 * Headache attributed to dural arteriovenous fistula
 * Headache attributed to cavernous angioma
 * Headache attributed to encephalotrigeminal or leptomeningeal angiomatosis (Sturge Weber syndrome)
 * Headache attributed to arteritis
 * Headache attributed to giant cell arteritis (GCA)
 * Headache attributed to primary central nervous system (CNS) angiitis
 * Headache attributed to secondary central nervous system (CNS) angiitis
 * Carotid or vertebral artery pain
 * Headache or facial or neck pain attributed to arterial dissection
 * Post-endarterectomy headache
 * Carotid angioplasty headache
 * Headache attributed to intracranial endovascular procedures
 * Angiography headache
 * Headache attributed to cerebral venous thrombosis (CVT)
 * Headache attributed to other intracranial vascular disorder
 * CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
 * MELAS (eitochondrial encephalopathy, lactic acidosis and stroke-like episodes)
 * Headache attributed to benign angiopathy of the central nervous system
 * Headache attributed to pituitary apoplexy

ICHD 7, ICD10 G44.82: Headache attributed to non-vascular intracranial disorder

 * Headache attributed to high cerebrospinal fluid pressure
 * Headache attributed to idiopathic intracranial hypertension (IIH)
 * Headache attributed to intracranial hypertension secondary to metabolic, toxic or hormonal causes
 * Headache attributed to intracranial hypertension secondary to hydrocephalus
 * Headache attributed to low cerebrospinal fluid pressure
 * Post-dural puncture headache
 * CSF fistula headache
 * Headache attributed to spontaneous (or idiopathic) low CSF pressure
 * Headache attributed to non-infectious inflammatory disease
 * Headache attributed to neurosarcoidosis
 * Headache attributed to aseptic (non-infectious) meningitis
 * Headache attributed to other non-infectious inflammatory disease
 * Headache attributed to lymphocytic hypophysitis
 * Headache attributed to intracranial neoplasm
 * Headache attributed to increased intracranial pressure or hydrocephalus caused by neoplasm
 * Headache attributed directly to neoplasm
 * Headache attributed to carcinomatous meningitis
 * Headache attributed to hypothalamic or pituitary hyper- or hyposecretion
 * Headache attributed to intrathecal injection
 * Headache attributed to epileptic seizure
 * Hemicrania epileptica
 * Post-seizure headache
 * Headache attributed to Chiari malformation type I (CM1)
 * [[Lymphocytic pleocytosis|Syndrome of transient headache and neurological deficits with cerebrospinal fluid

lymphocytosis]] (HaNDL)
 * Headache attributed to other non-vascular intracranial disorder

ICHD 8, ICD10 G44.4 or G44.83: Headache attributed to a substance or its withdrawal

 * Headache induced by acute substance use or exposure
 * Nitric oxide (NO) donor-induced headache
 * Immediate NO donor-induced headache
 * Delayed NO donor-headache
 * Phosphodiesterase (PDE) inhibitor-induced headache
 * Carbon monoxide-induced headache
 * Alcohol-induced headache.
 * Immediate alcohol-induced headache
 * Delayed alcohol-induced headache
 * Headache induced by food components and additives
 * Monosodium glutamate-induced headache
 * Cocaine-induced headache
 * Cannabis-induced headache
 * Histamine-induced headache
 * Immediate histamine-induced headache
 * Delayed histamine-induced headache
 * Calcitonin gene-related peptide (CGRP)-induced headache
 * Immediate CGRP-induced headache
 * Delayed CGRP-induced headache
 * Headache as an acute adverse event attributed to medication used for other indications
 * Headache attributed to other acute substance use or exposure
 * Medication-overuse headache (MOH)
 * Ergotamine-overuse headache
 * Triptan-overuse headache
 * Analgesic-overuse headache
 * Opioid-overuse headache
 * Combination analgesic-overuse headache
 * Medication-overuse headache attributed to combination of acute medications
 * Headache attributed to other medication overuse
 * Probable medication-overuse headache
 * Headache as an adverse event attributed to chronic medication
 * Exogenous hormone-induced headache
 * Headache attributed to substance withdrawal
 * caffeine-withdrawal headache
 * opioid-withdrawal headache
 * Oestrogen-withdrawal headache
 * Headache attributed to withdrawal from chronic use of other substances

ICHD 9, ICD10 G44.821 or G44.881: Headache attributed to infection

 * Headache attributed to intracranial infection
 * Headache attributed to bacterial meningitis
 * Headache attributed to lymphocytic meningitis
 * Headache attributed to encephalitis
 * Headache attributed to brain abscess
 * Headache attributed to subdural empyema
 * Headache attributed to systemic infection
 * Headache attributed to systemic bacterial infection
 * Headache attributed to systemic viral infection
 * Headache attributed to other systemic infection
 * Headache attributed to HIV/AIDS
 * Chronic post-infection headache
 * Chronic post-bacterial meningitis headache

ICHD 10, ICD10 G44.882: Headache attributed to disorder of homeostasis

 * Headache attributed to hypoxia and/or hypercapnia
 * High-altitude headache
 * Diving headache
 * Sleep apnoea headache
 * Dialysis headache
 * Headache attributed to arterial hypertension
 * Headache attributed to phaeochromocytoma
 * Headache attributed to hypertensive crisis without hypertensive encephalopathy
 * Headache attributed to hypertensive encephalopathy
 * Headache attributed to pre-eclampsia
 * Headache attributed to eclampsia
 * Headache attributed to acute pressor response to an exogenous agent
 * Headache attributed to hypothyroidism
 * Headache attributed to fasting
 * Cardiac cephalalgia
 * Headache attributed to other disorder of homoeostasis

ICHD 11, ICD10 G44.84: Headache or facial pain attributed to disorder of cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other facial or cranial structures

 * Headache attributed to disorder of cranial bone
 * Headache attributed to disorder of neck
 * Cervicogenic headache
 * Headache attributed to retropharyngeal tendonitis
 * Headache attributed to craniocervical dystonia
 * Headache attributed to disorder of eyes
 * Headache attributed to acute glaucoma
 * Headache attributed to refractive errors
 * Headache attributed to heterophoria or heterotropia (latent or manifest squint)
 * Headache attributed to ocular inflammatory disorder
 * Headache attributed to disorder of ears
 * Headache attributed to rhinosinusitis
 * Headache attributed to disorder of teeth, jaws or related structures
 * Headache or facial pain attributed to temporomandibular joint (TMJ) disorder
 * Headache attributed to other disorder of cranium, neck, eyes, ears, nose, sinuses,

teeth, mouth or other facial or cervical structures

ICHD 12, ICD10 R51: Headache attributed to psychiatric disorder

 * Headache attributed to somatization disorder
 * Headache attributed to psychotic disorder

ICHD 13, ICD10 G44.847, G44.848, or G44.85: Cranial neuralgias and central causes of facial pain

 * ICHD 13.1, ICD10 G44.847: Trigeminal neuralgia


 * Glossopharyngeal neuralgia
 * Nervus intermedius neuralgia
 * Superior laryngeal neuralgia
 * Nasociliary neuralgia
 * Supraorbital neuralgia
 * Other terminal branch neuralgias
 * Occipital neuralgia
 * Neck-tongue syndrome
 * External compression headache
 * Cold-stimulus headache
 * Constant pain caused by compression, irritation or distortion of cranial nerves or upper cervical roots by structural lesions
 * Optic neuritis
 * Ocular diabetic neuropathy
 * Head or facial pain attributed to herpes zoster
 * Head or facial pain attributed to acute herpes zoster
 * Post-herpetic neuralgia
 * Tolosa–Hunt syndrome
 * Opthalamoplegic migraine
 * Central causes of facial pain
 * Anaesthesia dolorosa
 * Central post-stroke pain
 * Facial pain attributable to multiple sclerosis
 * Persistent idiopathic facial pain (the IHS's preferred term for atypical facial pain)
 * Burning mouth syndrome
 * Other cranial neuralgia or other centrally mediated facial pain

ICHD 14, ICD10 R51: Other headache, cranial neuralgia, central or primary facial pain

 * Headache not elsewhere classified
 * Headache unspecified